A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
The present invention relates to image information processing and more particularly to performing variable magnification of an image.
The prior art includes several methods and apparatus for magnifying images. Many of these are described below.
U.S. Pat. No. 4,153,896 teaches compressing or expanding an image such as a symbol, character or text, in a first direction followed by compressing or expanding the image in a second direction. The image to be compressed or expanded is divided up by a grid defining a large number of square areas in an image wherein each area is represented by a clock cycle in each direction. The compression or expansion is accomplished by utilizing an averaging circuit which provides a signal indicating the value of the resulting image.
U.S. Pat. No. 4,503,469 teaches a picture image enlarging/reducing system wherein image magnification by a desired factor is achieved by first enlarging the image by an integer factor greater than the desired factor and then multiplying the enlarged image by a correction coefficient corresponding to the ratio of the desired factor to the integer factor.
U.S. Pat. No. 4,532,605 is directed to forming a zoom operation on a displayed image and maintaining a fixed width of each line of the zoomed image regardless of the degree of magnification of the zoomed image.
U.S. Pat. No. 4,569,681 is directed to enlarging a binary image by inserting expansion rows and columns between previously existing rows and columns and setting the value of the expansion rows and columns equal to the value of one or both of the adjacent previously existing rows and columns.
U.S. Pat. No. 4,631,751 is directed to enlarging a binary image by rotating the image 90 degrees, inserting expansion rows into the image, building the expansion rows based upon the values of the neighboring rows, rotating the image another 90 degrees, inserting additional blank rows, and filling those blank rows based upon the values of adjacent rows.
U.S. Pat. No. 4,633,503 is directed to a video zoom processor by mapping each input pixel into at most four adjacent output pixels wherein each sampled input pixel is skilled, segmented and accumulated into four locations in the image memory.
U.S. Pat. No. 4,675,830 is directed to a method for producing scalable contour data. The method stretches and compresses character contours to bring specified contour points into proper alignment with a bit map grid.
U.S. Pat. No. 4,698,778 is directed to variable magnification of half tone images such as photographs or painted pictures. This is accomplished by utilizing one of a plurality of mother matrix patterns that is specified in accordance with the desired magnification.
U.S. Pat. No. 4,754,270 is directed to generating a variable size image on a display from a matrix of horizontal and vertical pixel information stored in memory by utilizing vertical and horizontal address counters which are incremented based on the desired magnification.
U.S. Pat. No. 4,774,581 is directed to a digital video zoom system which includes circuitry for writing image samples into a memory at a standard rate and for reading samples from the memory at a reduced rate.
U.S. Pat. No. 4,809,083 is directed to enlarging or reducing an image at a desired magnification in a facsimile, copying machine or the like. This is accomplished by continuously varying a ratio of a reading resolution to a recording density.
U.S. Pat. No. 4,827,433 is directed to changing magnification of image data applicable to a digital copier, facsimile or the like. This is accomplished by sampling original image data at a predetermined rate based on the desired magnification.
U.S. Pat. No. 4,833,625 is directed to an image viewing station wherein digitized image data at any size from any different modalities is stored in an original format and can be magnified or minified for display to a user. Magnification is performed by producing interpolated image data for each pixel of a magnified image based on the weighted sum of grey levels present of each pixels four nearest neighboring pixels, including pixels from other rows or columns. Minification is performed by discarding pixels to achieve the desired minification.
The present invention includes a method of expanding an image stored in a first array including the steps of separating the first array into a plurality of rows, each row having a first plurality of data elements, each element having a value, and separately expanding each row from a first plurality of data elements in the first array to a second plurality of data elements in a second array including the steps of correlating each of the first plurality of data elements to at least one of the second plurality of data elements, and distributing the value of selected elements of the first plurality of data elements to correlated data elements of the second plurality of data elements. In addition, the present invention includes an apparatus for expanding an image stored in a first array including apparatus for separating the first array into a plurality of rows, each row having a first plurality of data elements, each element having a value, and apparatus for separately expanding each row from a first plurality of data elements in the first array to a second plurality of data elements in a second array including apparatus for correlating each of the first plurality of data elements to at least one of the second plurality of data elements, and apparatus for distributing the value of selected elements of the first plurality of data elements to correlated data elements of the second plurality of data elements.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.